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Plakortide E (85), which is isolated from the Jamaican marine sponge Plakortis halichondrioides, contains a five-membered peroxide ring, with the oxygen atoms are linked to tertiary C4 and C6 centers.34,57 In this thesis, the total synthesis of plakortide E (85) is described. A novel palladium-catalyzed approach towards 1,2-dioxolanes has been developed. A lipase-catalyzed kinetic resolution was employed to provide optically pure 1,2-dioxolane central cores. Coupling of the central cores and side chains was achieved by a Negishi reaction. All four isomeric structures of plakortide E methyl ester, namely, 86a-d were synthesized, and one of these molecules, 86d proved to be natural plakortide E methyl ester on the basis of 1H, 13C NMR spectra and specific rotation. With plakortide E methyl ester (4S,6R, 10R)-(-)- cis-(86d) and its other three isomers in hand, we successfully converted them into plakortone B (3S,4S,6 R,10R)-(87a), and its isomers ent-87a, 87b and ent-87b via an intramolecular oxa-Michael addition/lactonization cascade reaction. Saponification converted 1,2-dioxolane 86d into plakortide E (85a) whose absolute configuration (4S,6 R,10R) was confirmed by comparison of spectral and physical data with those previously reported.35b / Sun, Xiaoyu. / Adviser: Henry N. C. Wong. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 183-195). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

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Thesis (Ph. D.)--Institute of Paper Chemistry, 1978. / Bibliography: leaves 111-113.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 71-79). Also available via the World Wide Web.

Thesis (Ph. D.)--University of Hong Kong, 2005.

Thesis (Ph. D.)--University of Chicago, 1936. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Description based on print version record. Bibliographical foot-notes.

Thesis (DTech (Biomedical Technology))--Cape Peninsula University of Technology, 2009 / Many environmental, physiological, and genetic factors have been shown to impair sperm function through oxidative damage. Oxidative stress (OS) arises as a consequence of excessive reactive oxygen species (ROS) production and/or impaired antioxidant defence mechanisms. The decline in male reproductive health generated considerable public and scientific concerns about the possible role of environmental contaminants. A better understanding of how OS affects sperm function will be beneficial as it might help in the design of new and effective treatment strategies to combat the problem of increasing male subfertility. Studies have suggested that antioxidant nutrients and/or medicines play a protective role in human health. Crude red palm oil (RPO) is known to be the richest natural plant source of antioxidants such as carotenoids, tocopherols and metalloporpheryns. The aims of this study were twofold: (i) To establish an in vivo animal model of OS by exposing rat to organic hydroperoxide such as t-butyl hydroperoxide (tbHP) and cumene hydroperoxide (cHP) through repeated intraperitoneal injections that can be used for studying these effects on testicular tissue, epididymal sperm and sperm function as well as male reproductive parameters in general. (ii) To investigate the effects of a RPO supplemented diet on male reproductive parameters and tissue in animals exposed to OS. In the first part of the study, male Wistar rats aged 10-12 weeks were randomly placed in groups and received standard rat chow (SRC) and water ad lib. Animals were injected intraperitoneally with saline (0.5 ml), t-butyl hydroperoxide (5µM, 10µM, 20µM and 40µM; 0.5 ml) or cumene hydroperoxide cHP (2.5µM, 5µM, 10µM and 20µM; 0.5 ml) over a 60 day period. In the second part, male Wistar rats aged 10-12 weeks were placed randomly in three groups and fed with SRC. Group 1 received no supplement while the food of groups 2 and 3 were supplemented with 2 mL and 4 mL RPO (in 25 gm SRC/day) respectively. Each group was further divided into 3 subgroups and injected intraperitoneally daily with either saline, 10µM cHP or 20µM tbHP respectively. This was done for 5 consecutive days per week over a 60 day period. Sperm concentrations, and motility, lipid peroxidation, superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) activities as well as apoptosis were assessed.